Continuous additive manufacturing methods

ABSTRACT

A continuous method of manufacturing adhesives is provided. The method includes obtaining an actinic radiation-polymerizable adhesive precursor composition disposed on a major surface of an actinic radiation-transparent substrate and irradiating a first portion of the actinic radiation-polymerizable adhesive precursor composition through the actinic radiation-transparent substrate for a first irradiation dosage. The method further includes moving the actinic radiation-transparent substrate and irradiating a second portion of the actinic radiation-polymerizable adhesive precursor composition through the actinic radiation-transparent substrate for a second irradiation dosage. Optionally, the method also includes irradiating a third portion of the actinic radiation-polymerizable adhesive precursor composition through the actinic radiation-transparent substrate prior to moving the substrate. The first irradiation dosage and the third irradiation dosage are often not the same, thereby forming an integral adhesive having a variable thickness in an axis normal to the actinic radiation-transparent substrate.

TECHNICAL FIELD

The present disclosure relates to continuous methods for additivemanufacturing of adhesives.

BACKGROUND

In various industries, components of devices are joined together usingan adhesive, such as a pressure sensitive adhesive, a hot melt adhesive,or a structural adhesive. As devices are miniaturized, the need forhigher precision delivery of adhesives increases. Moreover, there arecertain shapes of adhesives that cannot be prepared by die-cutting of anadhesive, for instance a wedge shape.

SUMMARY

The present disclosure relates to additive manufacturing of adhesives.It has been discovered that there exists a need for additional methodsfor manufacturing adhesives, such as continuous methods.

In a first aspect, a continuous method of making an adhesive isprovided. The method includes obtaining an actinicradiation-polymerizable adhesive precursor composition disposed on amajor surface of an actinic radiation-transparent substrate andirradiating a first portion of the actinic radiation-polymerizableadhesive precursor composition through the actinic radiation-transparentsubstrate for a first irradiation dosage to form a first adhesive. Themethod further includes moving the actinic radiation-transparentsubstrate and irradiating a second portion of the actinicradiation-polymerizable adhesive precursor composition through theactinic radiation-transparent substrate for a second irradiation dosageto form a second adhesive.

In a second aspect, another continuous method of making an adhesive isprovided. The method includes obtaining an actinicradiation-polymerizable adhesive precursor composition disposed on amajor surface of an actinic radiation-transparent substrate andirradiating a first portion of the actinic radiation-polymerizableadhesive precursor composition through the actinic radiation-transparentsubstrate for a first irradiation dosage. The method further includesirradiating a second portion of the actinic radiation-polymerizableadhesive precursor composition through the actinic radiation-transparentsubstrate for a second irradiation dosage and moving the actinicradiation-transparent substrate. The first portion and the secondportion are adjacent to or overlapping with each other and the firstirradiation dosage and the second irradiation dosage are not the same,thereby forming an integral adhesive having a variable thickness in anaxis normal to the actinic radiation-transparent substrate.

The above summary of the present disclosure is not intended to describeeach disclosed aspect or every implementation of the present disclosure.The description that follows more particularly exemplifies illustrativeembodiments. In several places throughout the application, guidance isprovided through lists of examples, which examples can be used invarious combinations. In each instance, the recited list serves only asa representative group and should not be interpreted as an exclusivelist.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of an apparatus for use in anexemplary method according to the present disclosure.

FIG. 2 is a schematic cross-sectional view of an apparatus for use inanother exemplary method according to the present disclosure.

FIG. 3 is a schematic cross-sectional view of an apparatus for use in afurther exemplary method according to the present disclosure.

FIG. 4 is a schematic cross-sectional view of an apparatus for use inyet another exemplary method according to the present disclosure.

FIG. 5 is a schematic cross-sectional view of an apparatus for use in astill further exemplary method according to the present disclosure.

FIG. 6 is a schematic cross-sectional view of an apparatus for use in anadditional exemplary method according to the present disclosure.

FIG. 7 is a schematic cross-sectional view of an apparatus for use instill another exemplary method according to the present disclosure.

FIG. 8 is a schematic cross-sectional view of an apparatus for use inyet a further exemplary method according to the present disclosure.

FIG. 9 is a schematic cross-sectional view of an apparatus for use inanother additional exemplary method according to the present disclosure.

FIG. 10 is a schematic cross-sectional view of an exemplary irradiationsource for use according to the present disclosure.

FIGS. 11a and 11b are schematic cross-sectional views of anotherexemplary irradiation source for use according to the presentdisclosure.

FIG. 12 is a schematic cross-sectional view of a further exemplaryirradiation source for use according to the present disclosure.

FIG. 13 is a schematic cross-sectional view of an additional exemplaryirradiation source for use according to the present disclosure.

DETAILED DESCRIPTION

The present disclosure provides methods for the additive manufacturingof adhesives, such as continuous manufacturing of the adhesives. Incertain embodiments, integral adhesives having variations in thicknessare formed, while in other embodiments a plurality of adhesives havingapproximately the same thickness are formed.

For the following Glossary of defined terms, these definitions shall beapplied for the entire application, unless a different definition isprovided in the claims or elsewhere in the specification.

Glossary

Certain terms are used throughout the description and the claims that,while for the most part are well known, may require some explanation. Itshould be understood that, as used herein:

As used in this specification and the appended embodiments, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended embodiments, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

As used in this specification, the recitation of numerical ranges byendpoints includes all numbers subsumed within that range (e.g. 1 to 5includes 1, 1.5, 2, 2.75, 3, 3.8, 4, and 5).

Unless otherwise indicated, all numbers expressing quantities oringredients, measurement of properties and so forth used in thespecification and embodiments are to be understood as being modified inall instances by the term “about.” Accordingly, unless indicated to thecontrary, the numerical parameters set forth in the foregoingspecification and attached listing of embodiments can vary dependingupon the desired properties sought to be obtained by those skilled inthe art utilizing the teachings of the present disclosure. At the veryleast, and not as an attempt to limit the application of the doctrine ofequivalents to the scope of the claimed embodiments, each numericalparameter should at least be construed in light of the number ofreported significant digits and by applying ordinary roundingtechniques.

The terms “comprises” and variations thereof do not have a limitingmeaning where these terms appear in the description and claims.

The words “preferred” and “preferably” refer to embodiments of thedisclosure that may afford certain benefits, under certaincircumstances. However, other embodiments may also be preferred, underthe same or other circumstances. Furthermore, the recitation of one ormore preferred embodiments does not imply that other embodiments are notuseful, and is not intended to exclude other embodiments from the scopeof the disclosure.

The term “actinic radiation” refers to electromagnetic radiation thatcan produce photochemical reactions.

The term “dosage” means a level of exposure to of actinic radiation.

The term “integral” means composed of parts that together constitute awhole.

The term “(co)polymer” is inclusive of both homopolymers containing asingle monomer and copolymers containing two or more different monomers.

The term “(meth)acrylic” or “(meth)acrylate” is inclusive of bothacrylic and methacrylic (or acrylate and methacrylate). Acrylate andmethacrylate monomers, oligomers, or polymers are referred tocollectively herein as “acrylates”.

The term “aliphatic group” means a saturated or unsaturated linear orbranched hydrocarbon group. This term is used to encompass alkyl,alkenyl, and alkynyl groups, for example.

The term “alkyl group” means a saturated hydrocarbon group that islinear, branched, cyclic, or combinations thereof and typically has 1 to20 carbon atoms. In some embodiments, the alkyl group contains 1 to 18,1 to 12, 1 to 10, 1 to 8, 1 to 6, or1 to 4 carbon atoms. Examples ofalkyl group include without limitation, methyl, ethyl, isopropyl,t-butyl, heptyl, dodecyl, octadecyl, amyl, 2-ethylhexyl, and the like.The term “alkylene group” refers to a divalent alkyl group.

The term “alicyclic group” means a cyclic hydrocarbon group havingproperties resembling those of aliphatic groups. The term “aromaticgroup” or “aryl group” means a mono- or polynuclear aromatic hydrocarbongroup.

The term “pattern” with respect to an adhesive refers to a design of anadhesive that defines at least one aperture in the adhesive.

The term “solvent” refers to a substance that dissolves anothersubstance to form a solution.

The term “total monomer” refers to the combination of all monomers in anadhesive composition, including both in a polymerized reaction productand in optional additional materials.

Reference throughout this specification to “one embodiment,” “certainembodiments,” “one or more embodiments” or “an embodiment,” whether ornot including the term “exemplary” preceding the term “embodiment,”means that a particular feature, structure, material, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the certain exemplary embodiments of the presentdisclosure. Thus, the appearances of the phrases such as “in one or moreembodiments,” “in some embodiments,” “in certain embodiments,” “in oneembodiment,” “in many embodiments” or “in an embodiment” in variousplaces throughout this specification are not necessarily referring tothe same embodiment of the certain exemplary embodiments of the presentdisclosure. Furthermore, the particular features, structures, materials,or characteristics may be combined in any suitable manner in one or moreembodiments.

Various exemplary embodiments of the disclosure will now be described.Exemplary embodiments of the present disclosure may take on variousmodifications and alterations without departing from the spirit andscope of the disclosure. Accordingly, it is to be understood that theembodiments of the present disclosure are not to be limited to thefollowing described exemplary embodiments, but are to be controlled bythe limitations set forth in the claims and any equivalents thereof.

In a first aspect, a continuous method is provided. The method includesobtaining an actinic radiation-polymerizable adhesive precursorcomposition disposed on a major surface of an actinicradiation-transparent substrate and irradiating a first portion of theactinic radiation-polymerizable adhesive precursor composition throughthe actinic radiation-transparent substrate for a first irradiationdosage to form a first adhesive. The method further includes moving theactinic radiation-transparent substrate and irradiating a second portionof the actinic radiation-polymerizable adhesive precursor compositionthrough the actinic radiation-transparent substrate for a secondirradiation dosage to form a second adhesive.

In a second aspect, another continuous method of making an adhesive isprovided. The method includes obtaining an actinicradiation-polymerizable adhesive precursor composition disposed on amajor surface of an actinic radiation-transparent substrate andirradiating a first portion of the actinic radiation-polymerizableadhesive precursor composition through the actinic radiation-transparentsubstrate for a first irradiation dosage. The method further includesirradiating a second portion of the actinic radiation-polymerizableadhesive precursor composition through the actinic radiation-transparentsubstrate for a second irradiation dosage and moving the actinicradiation-transparent substrate. The first portion and the secondportion are adjacent to or overlapping with each other and the firstirradiation dosage and the second irradiation dosage are not the same,thereby forming an integral adhesive having a variable thickness in anaxis normal to the actinic radiation-transparent substrate.

The below disclosure relates to both the first and second aspects.

Such continuous methods are adaptable for manufacturing a variety ofadhesive structures. For instance, a continuous method can form a seriesor array of individual adhesives each separated from each other byapproximately the distance the substrate was moved in betweenirradiation of the separate adhesives. The individual adhesives in someembodiments have the same dimensions of height, length, and width aseach other. In contrast, the individual adhesives in other embodimentsdiffer from each other in at least one of height (i.e., z-direction froma major surface of the substrate), length, and width. Advantageously,the methods of the present disclosure provide the capability to easilymanufacture individual adhesives having a number of unique shapes due toemploying adaptable actinic radiation sources, from which the bounds anddosage of the actinic radiation determine the specific shape of anindividual adhesive. For instance, digital light projectors, laserscanning devices, and liquid crystal displays can all be controlled tochange the area and intensity of the actinic radiation that causescuring of the actinic radiation-polymerizable adhesive precursorcomposition.

As noted above, die-cutting of an adhesive is not readily capable offorming adhesives having a wedge shape. Similarly, die-cutting is notamenable to forming an adhesive that has a height gradient or otherunique shapes. The (continuous) methods of the present disclosure notonly provide a wide variety of shapes and gradients, but also canmanufacture multiple different shapes and heights on the same substrate.

Hence, in certain embodiments, methods of the first aspect furthercomprise irradiating a third portion of the actinicradiation-polymerizable adhesive precursor composition through theactinic radiation-transparent substrate prior to moving the substrate,wherein the first portion and the third portion are adjacent to oroverlapping with each other. When the first irradiation dosage and thethird irradiation dosage are not the same, an integral adhesive isformed comprising a variable thickness in an axis normal to the actinicradiation-transparent substrate. In certain embodiments, the time ofirradiation of the first dosage is shorter or longer than the time ofirradiation of the third dosage. In certain embodiments, the actinicradiation intensity of the first dosage is lower or higher than theactinic radiation intensity of the third dosage. In certain embodiments,irradiating the first portion occurs before irradiating the thirdportion, at the same time as irradiating the third portion, or acombination thereof.

Optionally, methods of the first aspect further comprise irradiating afourth portion of the actinic radiation-polymerizable adhesive precursorcomposition through the actinic radiation-transparent substrate. Whenthe second portion and the fourth portion are adjacent to or overlappingwith each other and the second irradiation dosage and the fourthirradiation dosage are not the same, a second integral adhesivecomprising a variable thickness in an axis normal to the major surfaceof the actinic radiation-transparent substrate. In certain embodiments,the time of irradiation of the second dosage is shorter or longer thanthe time of irradiation of the fourth dosage. In certain embodiments,the actinic radiation intensity of the second dosage is lower or higherthan the actinic radiation intensity of the fourth dosage. In certainembodiments, irradiating the second portion occurs before irradiatingthe fourth portion, at the same time as irradiating the fourth portion,or a combination thereof.

Alternatively, in certain embodiments the method comprises applying thesame irradiation dosage to a number of different portions of the actinicradiation-polymerizable adhesive precursor composition (e.g., to boththe first portion and the third portion), thereby forming a pattern ofadhesive having the same thickness in an axis normal to the majorsurface of the actinic radiation-transparent substrate. The patternincludes one or more individual adhesives that can be either integral orseparate from one or more other individual adhesives of the same height.

In certain embodiments, methods of the second aspect further compriseirradiating a third portion of the actinic radiation-polymerizableadhesive precursor composition through the actinic radiation-transparentsubstrate for a third irradiation dosage, after moving the substrate.Optionally, the first irradiation dosage and the third irradiationdosage are the same or different. Moreover, methods of the second aspectmay further comprise irradiating a fourth portion of the actinicradiation-polymerizable adhesive precursor composition through theactinic radiation-transparent substrate for a fourth irradiation dosage.The third portion and the fourth portion are adjacent to or overlappingwith each other and the third irradiation dosage and the fourthirradiation dosage are not the same, thereby forming an integraladhesive. In such embodiments, the actinic radiation-transparentsubstrate is moved after irradiating the fourth portion of the actinicradiation-polymerizable adhesive precursor composition through theactinic radiation-transparent substrate.

In most embodiments, the (e.g., integral) adhesive is a pressuresensitive adhesive (PSA), a structural adhesive, a structural hybridadhesive, a hot melt adhesive, or a combination thereof. For example,the adhesive is often prepared from an actinic radiation-polymerizableadhesive precursor composition comprising an acrylate, a two-partacrylate and epoxy system, a two-part acrylate and urethane system, or acombination thereof In certain embodiments, the actinicradiation-polymerizable adhesive precursor composition is a 100%polymerizable precursor composition, while in other embodiments theactinic radiation-polymerizable adhesive precursor composition comprisesat least one solvent, such as for instance and without limitation C4-C12alkanes (e.g., heptanes), alcohols (e.g., methanol, ethanol, orisopropanol), ethers, and esters.

The acrylic polymer can be, for example, an acrylic acid ester of anon-tertiary alcohol having from 1 to 18 carbon atoms. In someembodiments, the acrylic acid ester includes a carbon-to-carbon chainhaving 4 to 12 carbon atoms and terminates at the hydroxyl oxygen atom,the chain containing at least half of the total number of carbon atomsin the molecule.

Certain useful acrylic acid esters are polymerizable to a tacky,stretchable, and elastic adhesive. Examples of acrylic acid esters ofnontertiary alcohols include but are not limited to 2-methylbutylacrylate, isooctyl acrylate, lauryl acrylate, 4-methyl-2-pentylacrylate, isoamyl acrylate, sec-butyl acrylate, n-butyl acrylate,n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-decylacrylate, isodecyl acrylate, isodecyl methacrylate, and isononylacrylate. Suitable acrylic acid esters of nontertiary alcohols include,for example, 2-ethylhexyl acrylate and isooctylacrylate.

To enhance the strength of the adhesive, the acrylic acid ester may becopolymerized with one or more monoethylenically unsaturated monomersthat have highly polar groups. Such monoethylenically unsaturatedmonomer such as acrylic acid, methacrylic acid, itaconic acid,acrylamide, methacrylamide, N-substituted acrylamides (for example,N,N-dimethyl acrylamide), acrylonitrile, methacrylonitrile, hydroxyalkylacrylates, cyanoethyl acrylate, N-vinylpyrrolidone, N-vinylcaprolactam,and maleic anhydride. In some embodiments, these copolymerizablemonomers are used in amounts of less than 20% by weight of the adhesivematrix such that the adhesive is tacky at ordinary room temperatures. Insome cases, tackiness can be preserved at up to 50% by weight ofN-vinylpyrrolidone.

Especially useful are acrylate copolymers comprising at least 6% byweight acrylic acid, and in other embodiments, at least 8% by weight, orat least 10% by weight acrylic acid, each based on the total weight ofthe monomers in the acrylate copolymer. The adhesive may also includesmall amounts of other useful copolymerizable monoethylenicallyunsaturated monomers such as alkyl vinyl ethers, vinylidene chloride,styrene, and vinyltoluene.

In certain embodiments, adhesives according to the present disclosurecomprise two-part acrylate and epoxy systems. For instance, suitableacrylate-epoxy compositions are described in detail in U.S. ApplicationPublication No. 2003/0236362 (Bluem et al.) In certain embodiments,adhesives according to the present disclosure comprise two-part acrylateand urethane systems. For instance, suitable acrylate-urethanecompositions are described in detail in U.S. Pat. No. 4,950,696(Palazotto et al.)

Enhancement of the cohesive strength of the adhesive may also beachieved through the use of a crosslinking agent such as 1,6-hexanedioldiacrylate, with a photoactive triazine crosslinking agent such astaught in U.S. Pat. Nos. 4,330,590 (Vesley) and 4,329,384 (Vesley etal.), or with a heat-activatable crosslinking agent such as alower-alkoxylated amino formaldehyde condensate having C1-4 alkylgroups—for example, hexamethoxymethyl melamine or tetramethoxymethylurea or tetrabutoxymethyl urea. Crosslinking may be achieved byirradiating the composition with electron beam (or “e-beam”) radiation,gamma radiation, or x-ray radiation. Bisamide crosslinkers may be usedwith acrylic adhesives in solution.

In a typical photopolymerization method, a monomer mixture may beirradiated with actinic radiation, such as for example ultraviolet (UV)rays, in the presence of a photopolymerization initiator (i.e.,photoinitiators). Suitable exemplary photoinitiators are those availableunder the trade designations IRGACURE and DAROCUR from BASF(Ludwigshafen, Germany) and include 1-hydroxycyclohexyl phenyl ketone(IRGACURE 184), 2,2-dimethoxy-1,2-diphenylethan-1-one (IRGACURE 651),bis(2,4,6-trimethylbenzoyl)phenylphosphineoxide (IRGACURE 819),1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane -1-one(IRGACURE 2959), 2-benzyl-2-dimethylamino-1-(4-morpholinophenylbutanone(IRGACURE 369),2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (IRGACURE907), Oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone]ESACURE ONE (Lamberti S.p.A., Gallarate, Italy),2-hydroxy-2-methyl-1-phenyl propan-1-one (DAROCUR 1173),2,4,6-trimethylbenzoyldiphenylphosphine oxide (IRGACURE TPO), and2,4,6-trimethylbenzoylphenyl phosphinate (IRGACURE TPO-L). Additionalsuitable photoinitiators include for example and without limitation,benzyl dimethyl ketal, 2-methyl-2-hydroxypropiophenone, benzoin methylether, benzoin isopropyl ether, anisoin methyl ether, aromatic sulfonylchlorides, photoactive oximes, and combinations thereof. When used, aphotoinitiator is typically present in an amount between about 0.01 toabout 5.0 parts, or from 0.1 to 1.5 parts, per 100 parts by weight oftotal monomer.

In many embodiments, the method comprises post-curing the one or moreformed adhesives (e.g., the first adhesive, the second adhesive, theintegral adhesive, etc.), for instance post-curing using actinicradiation or heat. In such embodiments, by not requiring an adhesive tobe cured to the full extent needed for a particular application duringan initial irradiation, radiation variables can be focused onpolymerizing to form a desired shape and size.

The post-cure of the adhesive is optionally initiated using a thermalinitiator. Suitable thermal initiators include for example and withoutlimitation, 2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobisoisobutyronitrile (VAZO 64, available from E.I. du Pont deNemours Co.), 2,2′-azobis(2,4-dimethylpentanenitrile) (VAZO 52,available from E.I. du Pont de Nemours Co.),2,2′-azobis-2-methylbutyronitrile,(1,1′-azobis(1-cyclohexanecarbonitrile), 2,2′-azobis(methylisobutyrate), 2,2′-azobis(2-amidinopropane) dihydrochloride,2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile),4,4′-azobis(4-cyanopentanoic acid) and its soluble salts (e.g., sodium,potassium)benzoyl peroxide, acetyl peroxide, lauroyl peroxide, decanoylperoxide, dicetyl peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate,t-butylperoxypivalate, t-butylperoxy-2-ethylhexanoate, dicumyl peroxide,potassium persulfate, sodium persulfate, ammonium persulfate,combinations of the persulfates with sodium metabisulfite or sodiumbisulfite, benzoyl peroxide plus dimethylaniline, cumene hydroperoxideplus cobalt naphthenate, and combinations thereof. When used, a thermalinitiator is typically present in an amount from about 0.01 to about 5.0parts, or from 0.1 to 0.5 parts, per 100 parts by weight of totalmonomer.

The method often further comprises removing actinicradiation-polymerizable adhesive precursor composition remaining incontact with the adhesives (e.g., the first adhesive, the secondadhesive, the integral adhesive, etc.). Removing precursor compositionthat has not been polymerized after the irradiating may involve the useof gravity, a gas, a vacuum, a fluid, or any combination thereofOptionally, a suitable fluid for removing excess adhesive precursorcomposition includes a solvent. When the adhesive will be post-cured, itmay be particularly desirable to remove residual precursor compositionfrom being in contact with the adhesive, to minimize or prevent theaddition of adhesive material to the desired shape and size of theadhesive upon post-curing.

The temperature(s) at which methods according to the present disclosureare performed is not particularly limited. For methods employing anactinic radiation-polymerizable adhesive precursor composition that isin a liquid form at room temperature (e.g., 20-25 degrees Celsius), forsimplicity at least some of the various steps of the method aretypically performed at room temperature. For methods employing anactinic radiation-polymerizable adhesive precursor composition that isin a solid form at room temperature, at least some of the various stepsof the method may be performed at an elevated temperature above roomtemperature such that the actinic radiation-polymerizable adhesiveprecursor composition is in a liquid form. Elevated temperatures may beused through an entire method, or through such steps as formation of anadhesive, removal of unpolymerized actinic radiation-polymerizableadhesive precursor composition, and/or optional post-curing of theadhesive. In some embodiments, certain portions of the method areperformed at different temperatures, whereas in some other embodiments,the entire method is performed at one temperature. Suitable elevatedtemperatures include for instance and without limitation, above 25degrees Celsius and up to 150 degrees Celsius, up to 130 degreesCelsius, up to 110 degrees Celsius, up to 100 degrees Celsius, up to 90degrees Celsius, up to 80 degrees Celsius, up to 70 degrees Celsius, upto 60 degrees Celsius, up to 50 degrees Celsius, or up to 40 degreesCelsius. In certain embodiments, the method is performed at atemperature between 20 degrees Celsius and 150 degrees Celsius,inclusive; between 30 degrees Celsius and 150 degrees Celsius,inclusive; between 25 degrees Celsius and 100 degrees Celsius,inclusive; or between 25 degrees Celsius and 70 degrees Celsius,inclusive. The temperature employed is typically limited only by thelowest maximum temperature at which a material used in the method (e.g.,a substrate, an apparatus component, etc.) remains thermally stable.

In certain embodiments, the method is performed on an apparatus that isseparate from other materials used in an end application for the one ormore formed adhesives. In such embodiments, the method further comprisesremoving the first integral adhesive from the substrate, as discussed infurther detail below.

The resulting adhesive is an adhesive due to its ability to adhere twomaterials together. Characteristics such as specific peel force,tackiness, etc., are not particularly limited as long as the formedadhesive adheres two material together (e.g., two layers in a multilayerconstruction, two components of a device, and the like). Typically, sucha test involves disposing the formed adhesive between two substrates(one or both may be polymeric, glass, ceramic, or metal), lifting thearticle by the edges of one of the substrates, and observing whether ornot the second substrate remains attached to the article.

In certain embodiments, the adhesive comprises variations in index ofrefraction. Such variations are typically formed as artifacts of theirradiation of the actinic radiation-polymerizable adhesive precursorcomposition with the various irradiation sources. For instance, for anintegral adhesive having variability in its thickness, often there willbe a variation in the index of refraction between the portions of theintegral adhesive that were subjected to different dosages to form thevariability in the thickness.

Referring to FIG. 1, a schematic of an apparatus 100 for use inexemplary methods of the present disclosure is provided. The apparatusincludes an actinic radiation-transparent substrate 10 having a majorsurface 11 and an irradiation source 12 configured to direct actinicradiation through the actinic radiation-transparent substrate 10 atpredetermined dosages at predetermined locations. The apparatus 100further includes a means for depositing 14 a composition 16 onto themajor surface 11 of the actinic radiation-transparent substrate 10 and ameans for conveying 18 the actinic radiation-transparent substrate 10 orthe irradiation source 12 with respect to each other. In the apparatusillustrated in FIG. 1, the means for depositing 14 a composition 16 ontothe major surface 11 of the actinic radiation-transparent substrate 10comprises an open container holding a volume of the composition 16positioned adjacent to the substrate 10 such that a portion of the majorsurface 11 of the substrate 10 is in contact with the composition 16.The contact deposits the composition 16 on the major surface 11 of thesubstrate 10, then as the means for conveying 18 the substrate 10rotates, the composition 16 continues to be deposited on the portions ofthe major surface 11 of the substrate 10 that come into contact with thecomposition 16 held in the container 14.

In certain embodiments, the apparatus 100 further comprises an air knife20 configured to remove a composition from the substrate. Air knives arewell known in the art and use compressed air to blow off contaminants,excess materials, etc. from a product or apparatus.

The apparatus optionally further comprises a second substrate 22. Thesubstrate is not particularly limited in material or surface structure;for example the second substrate 22 illustrated in FIG. 1 comprises astructured sheet, in which at least one major surface 25 of the sheet isstructured (as opposed to flat and featureless). Suitable sheetmaterials include for instance and without limitation, polymericmaterials selected from polyethylene terephthalate, polyethylenenaphthalate, polycarbonate, polyimide, cycloolefin films, poly(methylmethacrylate), or a combination thereof. The second substrate may be afilm, such as a single layer film or multilayer film having either asmooth surface or structured surface. Suitable structured surfacesinclude microstructured surfaces or embossed surfaces. Typically, asecond substrate is employed to remove an adhesive from the actinicradiation-transparent substrate following irradiation from the actinicradiation. The second substrate 22 can be secured adjacent to andseparate from the actinic radiation-transparent substrate 10 using aroller 23 or other suitable means.

In certain embodiments, the apparatus 100 further comprises a scraper 24configured to scrape the substrate and/or a tacky roller 26 configuredto clean the substrate. Other cleaning mechanisms for removing adhesiveand/or un-polymerized composition from the substrate could alternativelybe employed to prepare the substrate for the deposition of additionalcomposition on its major surface, e.g., washing with a solvent.Moreover, in certain embodiments the substrate comprises a releasematerial coated on the major surface of the substrate to enhance theease of removal of the adhesive formed on the substrate. Suitablerelease materials include for instance and without limitation, siliconematerials and low adhesion coatings. One example of a suitable lowadhesion coating can be coated as a solution of polyvinyl N-octadecylcarbamate and a blend of silicone resins, as described in U.S. Pat. No.5,531,855 (Heinecke et al.)

In many embodiments, the actinic radiation-transparent substrate 10 isin the form of a cylinder. The means for depositing 14 a composition 16on a cylindrical substrate 10 may comprise rotating the cylinder (e.g.,actinic radiation-transparent substrate) through a volume of thecomposition 16 to apply the composition 16 on the major surface 11 ofthe substrate 10. Advantageously, it is not always necessary to havestrict control over the thickness of a composition that is deposited onthe substrate because the irradiation dosage from the irradiation sourceis selected to polymerize a predetermined shape and size of thecomposition, as opposed to polymerizing through an entire thickness ofthe composition regardless of its particular depth.

In certain embodiments of methods according to the present disclosure,in use the apparatus shown in FIG. 1 is operated as follows: A means forconveying 18 the actinic radiation-transparent substrate 10 rotates theactinic radiation-transparent substrate 10 through the means fordepositing 14 a composition 16, thereby depositing the composition 16 onthe major surface 11 of the substrate 10 with which it contacts. Anirradiation source 12 directs radiation through the actinicradiation-transparent substrate 10 at one or more predetermined dosagesat one or more predetermined locations. The composition 16 that has beenirradiated at least partially polymerizes, forming at least oneadhesive, such as the adhesive 17 and the adhesive 19, shown in FIG. 1.For example, the adhesive 17 comprises a variation in thickness as aresult of the specific irradiation provided by the irradiation source12. As the substrate 10 continues to rotate (in the direction of thearrow, for instance), an air knife 20 directs air towards the majorsurface 11 of the substrate 10 to assist in removing the composition 16remaining on the major surface 11 of the substrate 10 that was notpolymerized to form an adhesive. The excess composition 16 is preferablyreturned to the container 14 via gravity once it is no longer depositedon the substrate 10. Once a formed adhesive (e.g., the adhesive 27 andthe adhesive 29) reaches the second substrate 22 via rotation of theactinic radiation-transparent substrate 10, the adhesive (27, 29) istransferred from the major surface 11 of the substrate 10 to a majorsurface 25 of the second substrate 22. As the substrate 10 continues torotate, a scraper 24 contacts the major surface 11 of the substrate 10and removes residual adhesive from the substrate 10. Further, a tackyroller 26 contacts the major surface 11 of the substrate and removesresidual adhesive from the substrate 10. It will be understood that notevery apparatus 100 will include both or either of a scraper 24 and atacky roller 26, as these can be optional components.

For instance, referring to the first aspect, a method may includeobtaining an actinic radiation-polymerizable adhesive precursorcomposition 16 disposed on a major surface 11 of an actinicradiation-transparent substrate 10 and irradiating a first portion ofthe actinic radiation-polymerizable adhesive precursor compositionthrough the actinic radiation-transparent substrate 10 for a firstirradiation dosage to form a first adhesive 19. The method furtherincludes moving the actinic radiation-transparent substrate 10 andirradiating a second portion of the actinic radiation-polymerizableadhesive precursor composition through the actinic radiation-transparentsubstrate 10 for a second irradiation dosage to form a second adhesive17. In embodiments in which the method further includes irradiating athird portion of the actinic radiation-polymerizable adhesive precursorcomposition through the actinic radiation-transparent substrate 10 for athird irradiation dosage prior to moving the substrate, and the firstportion and the third portion are adjacent to or overlapping with eachother, an integral adhesive 19 is formed comprising a variable thicknessin an axis normal to the actinic radiation-transparent substrate 10 whenthe first irradiation dosage and the third irradiation dosage are notthe same.

Referring to the second aspect, a method may include obtaining anactinic radiation-polymerizable adhesive precursor composition 16disposed on a major surface 11 of an actinic radiation-transparentsubstrate 10 and irradiating a first portion of the actinicradiation-polymerizable adhesive precursor composition through theactinic radiation-transparent substrate 10 for a first irradiationdosage. The method further includes irradiating a second portion of theactinic radiation-polymerizable adhesive precursor composition throughthe actinic radiation-transparent substrate for a second irradiationdosage and moving the actinic radiation-transparent substrate. The firstportion and the second portion are adjacent to or overlapping with eachother and the first irradiation dosage and the second irradiation dosageare not the same, thereby forming an integral adhesive 19 having avariable thickness in an axis normal to the actinicradiation-transparent substrate 10.

Referring now to FIG. 2, a schematic of an apparatus 200 for use inexemplary methods of the present disclosure is provided. The apparatusincludes an actinic radiation-transparent substrate 210 having a majorsurface 211 and an irradiation source 212 configured to direct actinicradiation through the actinic radiation-transparent substrate 210 atpredetermined dosages at predetermined locations. The apparatus 200further includes a means for depositing 214 a composition 216 onto themajor surface 211 of the actinic radiation-transparent substrate 210 anda means for conveying 218 the actinic radiation-transparent substrate210 or the irradiation source 212 with respect to each other. Theschematic of the apparatus 200 shown in FIG. 2 further comprises an airknife 220 configured to remove nonpolymerized composition 216 from thesubstrate 210. Also, the apparatus 200 of certain embodiments includes asecond irradiation source 232 configured to irradiate one or moreadhesives (e.g., the adhesive 227 and the adhesive 229) through a secondsubstrate 222 as they pass by the second irradiation source 232.Typically, the use of a second irradiation source 232 is effective topost-cure the one or more adhesives. The second substrate 222 is often aconsumable material obtained separately from the apparatus, and in theillustrated embodiment, comprises a structured sheet, in which at leastone major surface 225 of the sheet is structured (as opposed to flat andfeatureless). The second substrate 222 can be secured adjacent to andseparate from the actinic radiation-transparent substrate 210 using aroller 223 or other suitable means. The apparatus 200 shown in FIG. 2further includes an actinic radiation-transparent film 230 having amajor surface 231. The actinic radiation-transparent film 230 is wrappedat least partially around the actinic radiation-transparent substrate210, and acts to protect the major surface 211 of the substrate 210 fromresidual composition 216 and adhesive material resistant to cleaning.

In use, the apparatus 200 operates similarly to the apparatus 100 ofFIG. 1 described above, including that the composition 216 that has beenirradiated at least partially polymerizes, forming at least oneadhesive, such as the adhesive 217 and the adhesive 219. Once a formedadhesive (e.g., the adhesive 227 and the adhesive 229) reaches a secondsubstrate 222 via rotation of the actinic radiation-transparentsubstrate 210, the adhesive (227, 229) is transferred from the majorsurface 211 of the substrate 210 to a major surface 225 of the secondsubstrate 222. Further, in certain embodiments, the formed adhesive(227, 229) is irradiated by the second irradiation source 232 topost-cure the adhesive prior to transfer from the (first) substrate 210to the second substrate 222.

Referring to FIG. 3, a schematic of an apparatus 300 for use inexemplary methods of the present disclosure is provided. The apparatusincludes an actinic radiation-transparent substrate 310 having a majorsurface 311 and an irradiation source 312 configured to direct actinicradiation through the actinic radiation-transparent substrate 310 atpredetermined dosages at predetermined locations. The apparatus 300further includes a means for depositing 314 a composition 316 onto themajor surface 311 of the actinic radiation-transparent substrate 310 anda means for conveying 318 the actinic radiation-transparent substrate310 or the irradiation source 312 with respect to each other. Theschematic of the apparatus 300 shown in FIG. 3 further comprises an airknife 320 configured to remove nonpolymerized composition 316 from thesubstrate 310, as well as a plurality of second irradiation sources 332configured to irradiate one or more adhesives (e.g., the adhesive 327and the adhesive 329) through a second substrate 322 as they pass by thesecond irradiation source 332. Typically, the use of at least one secondirradiation source 332 is effective to post-cure the one or moreadhesives. The second substrate 322 is often a consumable materialobtained separately from the apparatus, and in the illustratedembodiment, comprises a smooth sheet. The second substrate 322 can besecured adjacent to and separate from the actinic radiation-transparentsubstrate 310 using a roller 323 or other suitable means. In certainembodiments, the apparatus 300 further comprises a scraper 324configured to scrape the substrate 310 and/or a tacky roller 326configured to clean the substrate 310.

In use, the apparatus 300 operates similarly to the apparatus 100 ofFIG. 1 described above, including that the composition 316 that has beenirradiated at least partially polymerizes, forming at least oneadhesive, such as the adhesive 317 and the adhesive 319. Once a formedadhesive (e.g., the adhesive 327 and the adhesive 329) reaches a secondsubstrate 322 via rotation of the actinic radiation-transparentsubstrate 310, the adhesive (327, 329) is transferred from the majorsurface 311 of the substrate 310 to a major surface 325 of the secondsubstrate 322. Further, in certain embodiments, the formed adhesive(327, 329) is irradiated by one or more second irradiation sources 332to post-cure the adhesive prior to transfer from the (first) substrate310 to the second substrate 322.

Referring to FIG. 4, a schematic of an apparatus 400 for use inexemplary methods of the present disclosure is provided. The apparatusincludes an actinic radiation-transparent substrate 410 having a majorsurface 411 and an irradiation source 412 configured to direct actinicradiation through the actinic radiation-transparent substrate 410 atpredetermined dosages at predetermined locations. The apparatus 400further includes a means for depositing 414 a composition 416 onto themajor surface 411 of the actinic radiation-transparent substrate 410 anda means for conveying 418 the actinic radiation-transparent substrate410 or the irradiation source 412 with respect to each other.Optionally, an air knife 420 configured to remove nonpolymerizedcomposition 416 from the substrate 410 is provided with the apparatus.The schematic of the apparatus 400 shown in FIG. 4 further comprises amechanism 440 configured to remove one or more adhesives (e.g., theadhesive 429) through a second substrate 422 as they pass by themechanism. For instance, the mechanism can be a robotic mechanism havinga movable arm 442 and a replaceable end effector 444 configured todetach one or more adhesives 429 from the actinic radiation-transparentsubstrate 410. In the embodiment shown in FIG. 4, the end effector 444comprises a major surface 445 configured to be shaped to be an inverseof the shape of an upper major surface of the adhesive 429. Themechanism 440 is typically configured to place the adhesive 429 in alocation separate from the apparatus 400, such as on another substrate,on a device, on a release liner, in a storage container, etc. In certainembodiments, the apparatus 400 further comprises a scraper 424configured to scrape the substrate 410 and/or a tacky roller 426configured to clean the substrate 410.

In use, the apparatus 400 operates similarly to the apparatus 100 ofFIG. 1 described above, including that the composition 416 that has beenirradiated at least partially polymerizes, forming at least oneadhesive, such as the adhesive 417 and the adhesive 419. However, once aformed adhesive (e.g., the adhesive 427 and the adhesive 429) reachesthe mechanism 440 via rotation of the actinic radiation-transparentsubstrate 410, the adhesive (427, 429) is transferred from the majorsurface 411 of the substrate 410 to a major surface 445 of the endeffector 444 of the mechanism 440.

Referring to FIG. 5, a schematic of an apparatus 500 for use inexemplary methods of the present disclosure is provided. The apparatusincludes at least two rollers 552 and 518 (at least one of which isconfigured to convey an actinic radiation-transparent substrate 510),and an irradiation source 512 configured to direct actinic radiationthrough the actinic radiation-transparent substrate 510 at predetermineddosages at predetermined locations. The apparatus 500 further includes ameans for depositing 514 a composition 516 onto a major surface 511 ofthe actinic radiation-transparent substrate 510 and a means forconveying 518 the actinic radiation-transparent substrate 510 or theirradiation source 512 with respect to each other. The means fordepositing 514 comprises a container configured to dispense thecomposition 516 as a pool on the major surface 511 of the substrate 510.The actinic radiation-transparent substrate 510 is often a consumablematerial obtained separately from the apparatus as opposed to being acomponent of the apparatus. Optionally, an air knife 520 configured toremove nonpolymerized composition 516 from the substrate 510 where oneor more adhesives 517 and 519 are formed is provided with the apparatus500.

In certain embodiments, in use the apparatus shown in FIG. 5 is operatedas follows: A means for conveying 518 the actinic radiation-transparentsubstrate 510 drives a web of the actinic radiation-transparentsubstrate 510 through a plurality of rollers 550 that form a containmentarea to hold the composition 516 supplied by the means for depositing514 the composition 516 on the major surface 511 of the substrate 510with which it contacts. The means for depositing 514 in this embodimentis a container disposed above the actinic radiation-transparentsubstrate 510. An irradiation source 512 directs radiation through theactinic radiation-transparent substrate 510 at one or more predetermineddosages at one or more predetermined locations. The composition 516 thathas been irradiated at least partially polymerizes, forming at least oneadhesive, such as the adhesive 517 and the adhesive 519, shown in FIG.5. For example, the adhesive 517 comprises a variation in width ascompared to the adhesive 519, as a result of the specific irradiationprovided by the irradiation source 512. As the substrate 510 continuesto be driven from an unwind roller 552 to the means for conveying 518(e.g., a wind roller as shown in FIG. 5), an air knife 520 directs airtowards the major surface 511 of the substrate 510 to assist in removingthe composition 516 remaining on the major surface 511 of the substrate510 that was not polymerized to form an adhesive. The excess composition516 is preferably returned to the containment area defined by theplurality of rollers 550. Once a formed adhesive (e.g., the adhesive 527and the adhesive 529) reaches the wind roller 518, the web of actinicradiation transparent substrate 510 is wound up.

Referring to FIG. 6, a schematic of an apparatus 600 for use inexemplary methods of the present disclosure is provided. The apparatusincludes at least two rollers 652 and 618 (at least one of which isconfigured to convey an actinic radiation-transparent substrate 610),and an irradiation source 612 configured to direct actinic radiationthrough the actinic radiation-transparent substrate 610 at predetermineddosages at predetermined locations. The apparatus 600 further includes ameans for depositing 614 a composition 616 onto a major surface 611 ofthe actinic radiation-transparent substrate 610 and a means forconveying 618 the actinic radiation-transparent substrate 610 or theirradiation source 612 with respect to each other. The actinicradiation-transparent substrate 610 is often a consumable materialobtained separately from the apparatus as opposed to being a componentof the apparatus. The means for depositing 614 comprises a containerconfigured to dispense the composition 616 through a funnel 615 and as apool on the major surface 611 of the substrate 611. The apparatusfurther includes a dam roller 645 comprising a pair of spaced apartedges (not shown) configured to contact the actinicradiation-transparent substrate 610 and define a containment areabetween the edges to provide space for the pool of composition 616disposed on the actinic radiation-transparent substrate 610.

A further means may be provided to contact the dam roller 645 with theactinic radiation-transparent substrate 610 to assist in minimizingleakage of the composition 616 off the actinic radiation-transparentsubstrate 610. In the apparatus shown in FIG. 6, such a means includesthree press rollers 646, 647, and 648 and a belt 649, in which two ofthe press rollers 646, 647 are disposed adjacent to the dam roller 645and the third press roller 648 is disposed at a distance from the firsttwo press rollers 646, 647. The belt 649 is configured in a loop aroundthe three press rollers 646, 647, and 648 and disposed in contact withthe actinic radiation-transparent substrate 610. The three press rollers646, 647, and 648 are configured to apply force to the belt to maintainit in contact with the actinic radiation-transparent substrate 610. Asthe actinic radiation-transparent substrate 610 is conveyed, the belt649 traverses around the three press rollers 646, 647, and 648.

In use, the apparatus 600 operates similarly to the apparatus 500 ofFIG. 5 described above, including that as the substrate 610 continues tobe driven from an unwind roller 652 (as well as under the dam roller645) to the means for conveying 618 (e.g., a wind roller as shown inFIG. 6), an air knife 620 directs air towards the major surface 611 ofthe substrate 610 to assist in removing the composition 616 remaining onthe major surface 611 of the substrate 610 that was not polymerized toform an adhesive by irradiation from the actinic irradiation source 612.The excess composition 616 is preferably returned to the containmentarea defined by the dam roller 645. Once a formed adhesive (e.g., theadhesive 627 and the adhesive 629) reaches the wind roller 618, the webof actinic radiation transparent substrate 610 is wound up.

Referring to FIG. 7, a schematic of an apparatus 700 for use inexemplary methods of the present disclosure is provided. The apparatusincludes at least two rollers 752 and 718 (at least one of which isconfigured to convey an actinic radiation-transparent substrate 710)configured to convey an actinic radiation-transparent substrate 710 andan irradiation source 712 configured to direct actinic radiation throughthe actinic radiation-transparent substrate 710 at predetermined dosagesat predetermined locations. The apparatus 700 further includes a meansfor depositing 714 a composition 716 onto a major surface 711 of theactinic radiation-transparent substrate 710 and a means for conveying718 the actinic radiation-transparent substrate 710 or the irradiationsource 712 with respect to each other. The actinic radiation-transparentsubstrate 710 is often a consumable material obtained separately fromthe apparatus 700 as opposed to being a component of the apparatus. Theapparatus further includes a dam roller 745 comprising a pair of spacedapart edges (not shown) configured to contact the actinicradiation-transparent substrate 710 and define a containment areabetween the edges to provide space for the pool of composition 716disposed on the actinic radiation-transparent substrate 710. The meansfor depositing 714 comprises a container configured to dispense thecomposition 716 as a thin layer onto a surface of the dam roller 745,which travels around the dam roller 745 and forms a pool on the majorsurface 711 of the substrate 710.

A further means may be provided to contact the dam roller 745 with theactinic radiation-transparent substrate 710 to assist in minimizingleakage of the composition 716 off the actinic radiation-transparentsubstrate 710. In the apparatus shown in FIG. 7, such a means includestwo tension rollers 754 and 756, wherein the actinicradiation-transparent substrate 710 is fed over one tension roller 756,under the dam roller 745, and over the other tension roller 754. Thisconfiguration allows the tension rollers 754 and 756 to be configured toapply force to the actinic radiation-transparent substrate 710 tomaintain the substrate 710 in contact with the dam roller 745 as theactinic radiation-transparent substrate 710 is conveyed through theapparatus.

In use, the apparatus 700 operates similarly to the apparatus 500 ofFIG. 5 described above, including that as the substrate 710 continues tobe driven from an unwind roller 752 (as well as over the first tensionroller 756, under the dam roller 745, and over the second tension roller754) to the means for conveying 718 (e.g., a wind roller as shown inFIG. 7), an air knife 720 directs air towards the major surface 711 ofthe substrate 710 to assist in removing the composition 716 remaining onthe major surface 711 of the substrate 710 that was not polymerized toform an adhesive by irradiation from the actinic irradiation source 712.The excess composition 716 is preferably returned to the containmentarea defined by the dam roller 745. Once a formed adhesive (e.g., theadhesive 727 and the adhesive 729) reaches the wind roller 718, the webof actinic radiation transparent substrate 710 is wound up.

Referring to FIG. 8, a schematic of an apparatus 800 for use inexemplary methods of the present disclosure is provided. The apparatusincludes at least two rollers 852 and 818 (at least one of which isconfigured to convey an actinic radiation-transparent substrate 810)configured to convey an actinic radiation-transparent substrate 810 andan irradiation source 812 configured to direct actinic radiation throughthe actinic radiation-transparent substrate 810 at predetermined dosagesat predetermined locations. The apparatus 800 further includes a meansfor depositing 814 a composition 816 onto a major surface 811 of theactinic radiation-transparent substrate 810 and a means for conveying818 the actinic radiation-transparent substrate 810 or the irradiationsource 812 with respect to each other. The actinic radiation-transparentsubstrate 810 is often a consumable material obtained separately fromthe apparatus 800 as opposed to being a component of the apparatus. Theapparatus further includes a dam roller 845 comprising a pair of spacedapart edges (not shown) configured to contact the actinicradiation-transparent substrate 810 and define a containment areabetween the edges to provide space for the pool of composition 816disposed on the actinic radiation-transparent substrate 810. The meansfor depositing 814 comprises a container configured to dispense thecomposition 816 as a thin layer onto a surface of the dam roller 845,which travels around the dam roller 845 and forms a pool on the majorsurface 811 of the substrate 810.

A further means may be provided to contact the dam roller 845 with theactinic radiation-transparent substrate 810 to assist in minimizingleakage of the composition 816 off the actinic radiation-transparentsubstrate 810. In the apparatus shown in FIG. 8, such a means includestwo tension rollers 854 and 856, wherein the actinicradiation-transparent substrate 810 is fed over one tension roller 856,under the dam roller 845, and over the other tension roller 854. Thisconfiguration allows the tension rollers 854 and 856 to be configured toapply force to the actinic radiation-transparent substrate 810 tomaintain the substrate 810 in contact with the dam roller 845 as theactinic radiation-transparent substrate 810 is conveyed through theapparatus. In the apparatus shown in FIG. 8, the tension rollers aredisposed adjacent to the dam roller 845 such that the actinicradiation-transparent substrate 810 is in contact with over 50 percentof the circumference of the dam roller 845 to further assist inminimizing leakage of the composition 816 off the actinicradiation-transparent substrate 810.

In use, the apparatus 800 operates similarly to the apparatus 500 ofFIG. 5 described above, including that as the substrate 810 continues tobe driven from an unwind roller 852 (as well as over the first tensionroller 856, under the dam roller 845, and over the second tension roller854) to the means for conveying 818 (e.g., a wind roller as shown inFIG. 8). Further, in certain embodiments, the formed adhesive (e.g.,827, 829) is irradiated by one or more second irradiation sources 832 topost-cure the adhesive prior to winding up the substrate 810. An airknife 820 optionally directs air towards the major surface 811 of thesubstrate 810 to assist in removing the composition 816 remaining on themajor surface 811 of the substrate 810 that was not polymerized to forman adhesive by irradiation from the actinic irradiation source 812. Theexcess composition 816 is preferably returned to the containment areadefined by the dam roller 845. Once a formed adhesive (e.g., theadhesive 827 and the adhesive 829) reaches the wind roller 818, the webof actinic radiation transparent substrate 810 is wound up.

Referring to FIG. 9, a schematic of an apparatus 900 for use inexemplary methods of the present disclosure is provided. The apparatusincludes at least two rollers 952 and 918 (at least one of which isconfigured to convey an actinic radiation-transparent substrate 910),and an irradiation source 912 configured to direct actinic radiationthrough the actinic radiation-transparent substrate 910 at predetermineddosages at predetermined locations. The apparatus 900 further includes ameans for depositing 914 a composition 916 onto a major surface 911 ofthe actinic radiation-transparent substrate 910 and a means forconveying 918 the actinic radiation-transparent substrate 910 or theirradiation source 912 with respect to each other. The means fordepositing 914 comprises a die configured to dispense the composition916 on the major surface 911 of the substrate 910. In such embodiments,the composition 916 is preferably sufficiently viscous to remain on themajor surface 911 of the substrate 910 without leaking off of the sideedges of the substrate 910. The actinic radiation-transparent substrate910 is often a consumable material obtained separately from theapparatus 900 as opposed to being a component of the apparatus.Optionally, an air knife 920 configured to remove nonpolymerizedcomposition 916 from the substrate 910 where one or more adhesives 917and 919 are formed is provided with the apparatus 900.

A further optional component of the apparatus 900 is a blade 960 thatslices portions of the substrate 910 on which one or more adhesives(e.g., 927 and and/or 929) are disposed. In the embodiment shown in FIG.9, a stack 961 of pieces of substrate 910 comprising one or more formedadhesives is illustrated. In an alternate embodiment, the substrate 910on which one or more adhesives (e.g., 927 and/or 929) are formed arewound up on a wind roll (not shown).

In certain embodiments, in use the apparatus shown in FIG. 9 is operatedas follows: A die 914 deposits a composition 916 on a major surface 911of an actinic radiation-transparent substrate 910. An irradiation source912 directs radiation through the actinic radiation-transparentsubstrate 910 at one or more predetermined dosages at one or morepredetermined locations. The composition 916 that has been irradiated atleast partially polymerizes, forming at least one adhesive, such as theadhesive 917 and the adhesive 919, shown in FIG. 9. For example, theadhesive 917 comprises a variation in width as compared to the adhesive919, as a result of the specific irradiation provided by the irradiationsource 912. A means for conveying 918 the actinic radiation-transparentsubstrate 910 drives a web of the actinic radiation-transparentsubstrate 910 over a roller 952 to allow gravity to begin separating thecomposition 916 that was not polymerized to form an adhesive (e.g., 917and 919). As the substrate 910 continues to be driven from a firstroller 918 to a second roller 952, an air knife 920 directs air towardsthe major surface 911 of the substrate 910 to assist in removing thecomposition 916 remaining on the major surface 911 of the substrate 910.The excess composition 916 is preferably deposited in a container 958for recycling or reuse. Once a particular section of the substrate 910holding at least one formed adhesive (e.g., the adhesive 927 and/or theadhesive 929) reaches the blade 960, the blade 960 is employed and thatportion of actinic radiation transparent substrate 910 is sliced off(and optionally added to a stack 961 of substrate 910 pieces eachcomprising at least one formed adhesive 927.

Referring to each of FIGS. 1-9, the actinic radiation-transparentsubstrate comprises glass (e.g., in any of FIGS. 1-4) or a polymericmaterial (e.g., in any of FIGS. 1-9). When the actinicradiation-transparent substrate comprises a polymeric material, thesubstrate usually comprises a polymeric material selected frompolyethylene terephthalate, polyethylene naphthalate, polycarbonate,polyimide, cycloolefin films, poly(methyl methacrylate), or combinationsthereof. When the actinic radiation-transparent substrate comprisesglass, the substrate usually comprises a glass selected from sodiumborosilicate glass, soda-lime glass, and quartz glass. In certainembodiments, the substrate comprises a multilayer construction, forinstance a polymeric sheet, an adhesive layer, and a liner. Inembodiments in which the adhesive is intended to be transferred from themultilayer construction to another surface or substrate, the multilayerconstruction comprises a coating (e.g., a release coating) upon whichthe integral adhesive is disposed.

Each of FIGS. 1-9 referred to a means for conveying an actinicradiation-transparent substrate or an irradiation source with respect toeach other. The means for conveying generally includes mechanical meansas known in the manufacturing arts, such as a motor, a servo motor, astepper motor, or any combinations thereof. Often, a motor ultimatelydrives one or more rollers, which convey a substrate (e.g., a cylinderor web of indefinite length) and/or the irradiation source.

Referring to each of FIGS. 1-9, the actinic radiation is typicallyprovided by an irradiation source that is a digital light projector(DLP) with a light emitting diode (LED), a DLP with a lamp, a laserscanning device with a laser, a liquid crystal display (LCD) panel witha backlight, a photomask with a lamp, or a photomask with an LED. Moreparticularly, a schematic o is provided in FIG. 10 of a DLP with an LEDor lamp, schematics are provided in FIGS. 11a and 11b of a photomaskwith a lamp or LED, a schematic is provided in FIG. 12 of an LCD panelwith a backlight, and a schematic is provided in FIG. 13 of a laserscanning device with a laser.

Referring now to FIG. 10, a schematic is provided of an irradiationsource 1000 for use in exemplary methods of the present disclosure,comprising a DLP 1065 with an LED or a lamp 1066 (1066 represents eitheran LED or a lamp). The DLP 1065 includes a plurality of individuallymovable reflectors, such as first reflector 1062, second reflector 1063,and third reflector 1064. Each reflector is positioned at a specificangle to direct irradiation from the LED or lamp 1066 towards apredetermined location of a composition 1016 disposed on a major surface1011 of an actinic radiation-transparent substrate 1010. In use, theintensity and duration of the irradiation from the LED or lamp 1066 willimpact the depth of cure (e.g., polymerization) of the composition 1016in a direction normal to the major surface 1011 of the substrate 1010upon formation of one or more adhesives 1017 and 1019. For instance, oneportion 1017 b of integral adhesive 1017 has a greater thickness thananother portion 1017 a of the same integral adhesive 1017. This may beachieved by irradiating the portion 1017 b with a greater dosage thanthe portion 1017 a is irradiated. In contrast, adhesive 1019 has asingle thickness across its width due to receiving the same dosageacross its width. A benefit of employing a DLP is that the individualreflectors are readily adjustable (e.g., using computer controls) tochange the irradiation location and dosage and thereby the shape of theresulting formed adhesives, as needed without requiring a significantequipment alteration. DLPs are well-known in the art, for instance andwithout limitation, the apparatuses described in U.S. Pat. Nos.5,658,063 (Nasserbakht), U.S. Pat. No. 5,905,545 (Poradish et al.), U.S.Pat. No. 6,587,159 (Dewald), U.S. Pat. No. 7,164,397 (Pettitt et al.),U.S. Pat. no. 7,360,905 (Davis et al.), U.S. Pat. No. 8,705,133 (Lieb etal.), and U.S. Pat. No. 8,820,944 (Vasquez). Suitable DLPs arecommercially available, such as from Texas Instruments (Dallas, Tex.).As indicated above, either an LED or a lamp may be employed with a DLP.Suitable lamps may include a flash lamp, a low pressure mercury lamp, amedium pressure mercury lamp, and/or a microwave driven lamp. Theskilled practitioner can select a suitable LED or lamp light source toprovide the actinic radiation required to initiate polymerization for aparticular polymerizable composition, for instance, the UV LEDCBT-39-UV, available from Luminus Inc. (Sunnyvale, Calif.).

Referring now to FIGS. 11a and 11 b, schematics are provided includingan irradiation source 1100 comprising at least one photomask 1170 a and1170 b with an LED or a lamp 1166 (1166 represents either an LED or alamp), for use in exemplary methods of the present disclosure. A lens1167 having a convex surface 1168 is employed with the LED or lamp 1166to diffuse the irradiation across at least a portion of the one or morephotomasks 1170 a and 1170 b. As shown in FIG. 11 a, a first photomask1170 a is employed to direct irradiation from the LED or lamp 1166towards a predetermined location of a composition 1116 disposed on amajor surface 1111 of an actinic radiation-transparent substrate 1110.In use, the intensity and duration of the irradiation from the LED orlamp 1166 will impact the depth of cure (e.g., polymerization) of thecomposition 1116 in a direction normal to the major surface 1111 of thesubstrate 1110 upon formation of one or more adhesives 1117 and 1119.For instance, one portion 1117 b of integral adhesive 1117 has a greaterthickness than another portion 1017 a of the same integral adhesive1117. This may be achieved by employing more than one photomask. Forinstance, referring to FIG. 11 a, a photomask 1170 a is shown in which aplurality of portions 1171 a are provided through which irradiation canbe directed to cure the composition 1116. Referring now to FIG. 11 a, asecond photomask 1170 b is shown in which one portion 1117 b is providedthrough which irradiation can be directed to further cure thecomposition 1116. In the illustrated embodiment, the portion 1117 b hasa greater thickness than the portion 1117 a due to being irradiatedtwice; once using the first photomask 1170 a and once using the secondphotomask 1170 b; resulting in irradiation of the portion 1117 b with agreater dosage than the portion 1117 a. In contrast, adhesive 1119 has asingle thickness across its width due to receiving the same dosageacross its width by exposure to irradiation through just the firstphotomask 1170 a. While the photomasks in FIGS. 11a and 11b are shown ashaving opaque and transparent portions, the skilled practitioner willappreciate that photomasks including greyscale may be employed toachieve gradients in cure in different locations of the composition.Suitable photomasks are commercially available, for instance, NanoSculptPhotomasks from Infinite Graphics (Minneapolis, Minn.). Similar to usinga DLP, either an LED or a lamp may be employed with a photomask.

Referring to FIG. 12, a schematic is provided of an irradiation source1200 comprising a digital photomask 1272 (e.g., a LCD with a backlight1266), wherein the backlight comprises an LED or a lamp 1266 (1266represents either an LED or a lamp), for use in exemplary methods of thepresent disclosure. A lens 1267 having a convex surface 1268 is employedwith the backlight 1266 to diffuse the irradiation across at least aportion of the digital photomask 1272. In use, the intensity andduration of the irradiation from the backlight 1266 will impact thedepth of cure (e.g., polymerization) of the composition 1216 in adirection normal to the major surface 1211 of the substrate 1210 uponformation of one or more adhesives 1217 and 1219. For instance, oneportion 1217 b of integral adhesive 1217 has a greater thickness thananother portion 1217 a of the same integral adhesive 1217. This may beachieved by irradiating the portion 1217 b with a greater dosage thanthe portion 1217 a is irradiated. In contrast, adhesive 1219 has asingle thickness across its width due to receiving the same dosageacross its width. A benefit of employing a digital photomask is that theindividual pixels are readily adjustable (e.g., using computer controls)to change the irradiation location and dosage and thereby the shape ofthe resulting formed adhesives, as needed without requiring asignificant equipment alteration. Suitable LCDs are commerciallyavailable, for instance, the LCD LQ043T1DG28, available from SharpCorporation (Osaka, Japan).

Referring to FIG. 13, a schematic is provided of an irradiation source1300 comprising a laser scanning device 1362 with a laser 1366, for usein exemplary methods of the present disclosure. The laser scanningdevice 1362 includes at least one individually movable mirror. Eachmirror is positioned at a specific angle to direct irradiation from thelaser 1366 towards a predetermined location of a composition 1316disposed on a major surface 1311 of an actinic radiation-transparentsubstrate 1310. In use, the intensity and duration of the irradiationfrom the laser 1366 will impact the depth of cure (e.g., polymerization)of the composition 1316 in a direction normal to the major surface 1311of the substrate 1310 upon formation of one or more adhesives 1317 and1319. For instance, one portion 1317 b of integral adhesive 1317 has agreater thickness than another portion 1317 a of the same integraladhesive 1317. This may be achieved by irradiating the portion 1317 bwith a greater dosage than the portion 1317 a is irradiated. Incontrast, adhesive 1319 has a single thickness across its width due toreceiving the same dosage across its width. A benefit of employing alaser scanning device is that the individual mirror(s) are readilyadjustable (e.g., using computer controls) to change the irradiationlocation and dosage and thereby the shape of the resulting formedadhesives, as needed without requiring a significant equipmentalteration. Suitable laser scanning devices are commercially available,such as the JS2808 Galvanometer Scanner from Sino-Galvo (Beijing)Technology Co., LTD. (Beijing, China). The skilled practitioner canselect a suitable laser to provide the actinic radiation required toinitiate polymerization for a particular polymerizable composition, forinstance, the CUBE 405-100C Diode Laser System from Coherent Inc. (SantaClara, Calif.).

Accordingly, any of the above irradiation sources of the presentdisclosure are suitable for use in each of the apparatuses of thedisclosed embodiments herein. It is an advantage of these irradiationsources that they are readily configured to provide one or morepredetermined dosages of irradiation at one or more predeterminedlocations, allowing the manufacture of adhesives having variations insize and shape, particularly in thickness normal to a substrate.

Exemplary Embodiments

Embodiment 1 is a method of manufacturing adhesives. The method includesobtaining an actinic radiation-polymerizable adhesive precursorcomposition disposed on a major surface of an actinicradiation-transparent substrate and irradiating a first portion of theactinic radiation-polymerizable adhesive precursor composition throughthe actinic radiation-transparent substrate for a first irradiationdosage to form a first adhesive. The method further includes moving theactinic radiation-transparent substrate and irradiating a second portionof the actinic radiation-polymerizable adhesive precursor compositionthrough the actinic radiation-transparent substrate for a secondirradiation dosage to form a second adhesive.

Embodiment 2 is the method of embodiment 1, further includingirradiating a third portion of the actinic radiation-polymerizableadhesive precursor composition through the actinic radiation-transparentsubstrate to form a third adhesive prior to moving the substrate.

Embodiment 3 is the method of embodiment 1 or embodiment 2, wherein thefirst portion and the third portion are adjacent to or overlapping witheach other.

Embodiment 4 is the method of any of embodiments 1 to 3, wherein thefirst irradiation dosage and the third irradiation dosage are not thesame, thereby forming an integral adhesive comprising the first adhesiveand the third adhesive, the integral adhesive comprising a variablethickness in an axis normal to the actinic radiation-transparentsubstrate.

Embodiment 5 is the method of any of embodiments 1 to 4, furtherincluding post-curing the first adhesive.

Embodiment 6 is the method of embodiment 5, wherein the post-curingincludes using actinic radiation or heat.

Embodiment 7 is the method of any of embodiments 1 to 6, furtherincluding irradiating a fourth portion of the actinicradiation-polymerizable adhesive precursor composition through theactinic radiation-transparent substrate to form a fourth adhesive.

Embodiment 8 is the method of embodiment 7, wherein the second portionand the fourth portion are adjacent to or overlapping with each other,thereby forming a second integral adhesive comprising the secondadhesive and the fourth adhesive, the second integral adhesivecomprising a variable thickness in an axis normal to the major surfaceof the actinic radiation-transparent substrate.

Embodiment 9 is the method of any of embodiments 1 to 8, furtherincluding removing actinic radiation-polymerizable adhesive precursorcomposition from the first adhesive remaining in contact with theadhesive after the irradiating using a gas, a vacuum, a fluid, or acombination thereof

Embodiment 10 is the method of any of embodiments 1 to 9, furthercomprising removing the first adhesive from the substrate.

Embodiment 11 is the method of embodiment 10, wherein the first adhesiveis removed with a second substrate.

Embodiment 12 is the method of embodiment 11, wherein the secondsubstrate comprises a structured sheet.

Embodiment 13 is the method of embodiment 10, including removing thefirst integral adhesive from the substrate with a robot.

Embodiment 14 is the method of any of embodiments 10 to 13, furtherincluding cleaning the substrate.

Embodiment 15 is the method of any of embodiments 1 to 14, wherein thesubstrate is coated with a release material.

Embodiment 16 is the method of any of embodiments 1 to 15, wherein thesubstrate includes glass or a polymeric material.

Embodiment 17 is the method of any of embodiments 1 to 16, wherein thesubstrate is in the form of a cylinder.

Embodiment 18 is the method of embodiment 17, including rotating thecylinder through a container holding the actinic radiation-polymerizableadhesive precursor composition to dispose the actinicradiation-polymerizable adhesive precursor composition on the substrate.

Embodiment 19 is the method of any of embodiments 1 to 16, wherein theprecursor composition is disposed as a pool on the major surface of thesubstrate.

Embodiment 20 is the method of any of embodiments 1 to 19, wherein thetime of irradiation of the first dosage is shorter than the time ofirradiation of the second dosage.

Embodiment 21 is the method of any of embodiments 1 to 20, wherein theactinic radiation intensity of the first dosage is lower than theactinic radiation intensity of the second dosage.

Embodiment 22 is the method of any of embodiments 1 to 21, whereinirradiating the first portion occurs before irradiating the secondportion.

Embodiment 23 is the method of any of embodiments 1 to 22, whereinirradiating the first portion occurs at the same time as irradiating thesecond portion.

Embodiment 24 is the method of any of embodiments 1 to 23, wherein thefirst adhesive is a pressure sensitive adhesive (PSA), a structuraladhesive, a structural hybrid adhesive, a hot melt adhesive, or acombination thereof.

Embodiment 25 is the method of any of embodiments 1 to 24, wherein theactinic radiation-polymerizable adhesive precursor composition comprisesan acrylate, a two-part acrylate and epoxy system, a two-part acrylateand urethane system, or a combination thereof

Embodiment 26 is the method of any of embodiments 1 to 25, wherein theactinic radiation-polymerizable adhesive precursor composition comprisesan acrylate.

Embodiment 27 is the method of any of embodiments 1 to 26, wherein thephotoinitiator is selected from 1-hydroxy cyclohexyl phenyl ketone,2,2-dimethoxy-1,2-diphenylethan-1-one,bis(2,4,6-trimethylbenzoyl)phenylphosphineoxide,1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and2-hydroxy-2-methyl-1-phenyl propan-1-one.

Embodiment 28 is the method of any of embodiments 1 to 27, wherein theactinic radiation is provided by a digital light projector (DLP) with alight emitting diode (LED), a DLP with a lamp, a laser scanning devicewith a laser, a liquid crystal display (LCD) panel with a backlight, aphotomask with a lamp, or a photomask with an LED.

Embodiment 29 is the method of embodiment 28, wherein the lamp isselected from a flash lamp, a low pressure mercury lamp, a mediumpressure mercury lamp, and a microwave driven lamp.

Embodiment 30 is the method of any of embodiments 1 to 29, wherein thefirst adhesive adheres two materials together.

Embodiment 31 is the method of any of embodiments 1 to 30, wherein thefirst adhesive comprises variations in index of refraction.

Embodiment 32 is the method of any of embodiments 1 to 31, wherein thesubstrate comprises a multilayer construction.

Embodiment 33 is the method of embodiment 32, wherein the multilayerconstruction includes a polymeric sheet, an adhesive layer, and a liner.

Embodiment 34 is the method of embodiment 32 or embodiment 33, whereinthe multilayer construction includes a coating upon which the firstadhesive is disposed.

Embodiment 35 is the method of any of embodiments 1 to embodiment 34,wherein the actinic radiation-polymerizable adhesive precursorcomposition is a 100% polymerizable precursor composition.

Embodiment 36 is the method of any of embodiments 1 to 35, wherein theactinic radiation-polymerizable adhesive precursor composition includesat least one solvent.

Embodiment 37 is the method of embodiment 15, wherein the releasematerial comprises silicone.

Embodiment 38 the method of any of embodiments 1 to 37, wherein themethod is performed at a temperature between 20 degrees Celsius and 150degrees Celsius, inclusive.

Embodiment 39 is a method of manufacturing adhesives. The methodincludes obtaining an actinic radiation-polymerizable adhesive precursorcomposition disposed on a major surface of an actinicradiation-transparent substrate and irradiating a first portion of theactinic radiation-polymerizable adhesive precursor composition throughthe actinic radiation-transparent substrate for a first irradiationdosage. The method further includes irradiating a second portion of theactinic radiation-polymerizable adhesive precursor composition throughthe actinic radiation-transparent substrate for a second irradiationdosage and moving the actinic radiation-transparent substrate. The firstportion and the second portion are adjacent to or overlapping with eachother and the first irradiation dosage and the second irradiation dosageare not the same, thereby forming an integral adhesive comprising avariable thickness in an axis normal to the actinicradiation-transparent substrate.

Embodiment 40 is the method of embodiment 39, further includingirradiating a third portion of the actinic radiation-polymerizableadhesive precursor composition through the actinic radiation-transparentsubstrate for a third irradiation dosage, after moving the substrate.

Embodiment 41 is the method of embodiment 40, wherein the firstirradiation dosage and the third irradiation dosage are the same.

Embodiment 42 is th method of embodiment 40 or embodiment 41, furtherincluding irradiating a fourth portion of the actinicradiation-polymerizable adhesive precursor composition through theactinic radiation-transparent substrate for a fourth irradiation dosage.The third portion and the fourth portion are adjacent to or overlappingwith each other and the third irradiation dosage and the fourthirradiation dosage are not the same.

Embodiment 43 is the method of embodiment 42, further including movingthe actinic radiation-transparent substrate after irradiating the fourthportion of the actinic radiation-polymerizable adhesive precursorcomposition through the actinic radiation-transparent substrate.

Embodiment 44 is the method of any of embodiments 39 to 43, furtherincluding post-curing the integral adhesive.

Embodiment 45 is the method of embodiment 44, wherein the post-curingincludes using actinic radiation or heat.

Embodiment 46 is the method of any of embodiments 39 to 45, furtherincluding removing actinic radiation-polymerizable adhesive precursorcomposition from remaining in contact with the integral adhesive afterthe irradiating using a gas, a vacuum, a fluid, or a combinationthereof.

Embodiment 47 is the method of any of embodiments 39 to 46, furthercomprising removing the integral adhesive from the substrate.

Embodiment 48 is the method of embodiment 47, wherein the integraladhesive is removed with a second substrate.

Embodiment 49 is the method of embodiment 48, wherein the secondsubstrate includes a structured sheet.

Embodiment 50 is the method of embodiment 47, including removing theintegral adhesive from the substrate with a robot.

Embodiment 51 is the method of any of embodiments 47 to 50, furtherincluding cleaning the substrate.

Embodiment 52 is the method of any of embodiments 39 to 51, wherein thesubstrate is coated with a release material.

Embodiment 53 is the method of any of embodiments 39 to 52, wherein thesubstrate includes glass or a polymeric material.

Embodiment 54 is the method of any of embodiments 39 to 53, wherein thesubstrate is in the form of a cylinder.

Embodiment 55 is the method of embodiment 54, including rotating thecylinder through a container holding the actinic radiation-polymerizableadhesive precursor composition to dispose the actinicradiation-polymerizable adhesive precursor composition on the substrate.

Embodiment 56 is the method of any of embodiments 39 to 53, wherein theprecursor composition is disposed as a pool on the major surface of thesubstrate.

Embodiment 57 is the method of any of embodiments 39 to 56, wherein thetime of irradiation of the first dosage is shorter than the time ofirradiation of the second dosage.

Embodiment 58 is the method of any of embodiments 39 to 57, wherein theactinic radiation intensity of the first dosage is lower than theactinic radiation intensity of the second dosage.

Embodiment 59 is the method of any of embodiments 39 to 58, whereinirradiating the first portion occurs before irradiating the secondportion.

Embodiment 60 is the method of any of embodiments 39 to 59, whereinirradiating the first portion occurs at the same time as irradiating thesecond portion.

Embodiment 61 is the method of any of embodiments 39 to 60, wherein theintegral adhesive is a pressure sensitive adhesive (PSA), a structuraladhesive, a structural hybrid adhesive, a hot melt adhesive, or acombination thereof.

Embodiment 62 is the method of any of embodiments 39 to 61, wherein theactinic radiation-polymerizable adhesive precursor composition comprisesan acrylate, a two-part acrylate and epoxy system, a two-part acrylateand urethane system, or a combination thereof.

Embodiment 63 is the method of any of embodiments 39 to 62, wherein theactinic radiation-polymerizable adhesive precursor composition comprisesan acrylate.

Embodiment 64 is the method of any of embodiments 39 to 63, wherein thephotoinitiator is selected from 1-hydroxy cyclohexyl phenyl ketone,2,2-dimethoxy-1,2-diphenylethan-1-one,bis(2,4,6-trimethylbenzoyl)phenylphosphineoxide,1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and2-hydroxy-2-methyl-1-phenyl propan-1-one.

Embodiment 65 is the method of any of embodiments 39 to 64, wherein theactinic radiation is provided by a digital light projector (DLP) with alight emitting diode (LED), a DLP with a lamp, a laser scanning devicewith a laser, a liquid crystal display (LCD) panel with a backlight, aphotomask with a lamp, or a photomask with an LED.

Embodiment 66 is the method of embodiment 65, wherein the lamp isselected from a flash lamp, a low pressure mercury lamp, a mediumpressure mercury lamp, and a microwave driven lamp.

Embodiment 67 is the method of any of embodiments 39 to 66, wherein theintegral adhesive adheres two materials together.

Embodiment 68 is the method of any of embodiments 39 to 67, wherein theintegral adhesive comprises variations in index of refraction.

Embodiment 69 is the method of any of embodiments 39 to 68, wherein thesubstrate comprises a multilayer construction.

Embodiment 70 is the method of embodiment 69, wherein the multilayerconstruction comprises a polymeric sheet, an adhesive layer, and aliner.

Embodiment 71 is the method of embodiment 69 or embodiment 70, whereinthe multilayer construction includes a coating upon which the integraladhesive is disposed.

Embodiment 72 is the method of any of embodiments 39 to embodiment 71,wherein the actinic radiation-polymerizable adhesive precursorcomposition is a 100% polymerizable precursor composition.

Embodiment 73 is the method of any of embodiments 39 to 72, wherein theactinic radiation-polymerizable adhesive precursor composition includesat least one solvent.

Embodiment 74 is the method of embodiment 73, wherein the releasematerial comprises silicone.

Embodiment 75 the method of any of embodiments 39 to 74, wherein themethod is performed at a temperature between 20 degrees Celsius and 150degrees Celsius, inclusive.

EXAMPLES

These Examples are merely for illustrative purposes and are not meant tobe overly limiting on the scope of the appended claims. Notwithstandingthat the numerical ranges and parameters setting forth the broad scopeof the present disclosure are approximations, the numerical values setforth in the specific examples are reported as precisely as possible.Any numerical value, however, inherently contains certain errorsnecessarily resulting from the standard deviation found in theirrespective testing measurements. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical parameter should at least beconstrued in light of the number of reported significant digits and byapplying ordinary rounding techniques.

Summary of Materials

Unless otherwise noted, all parts, percentages, ratios, etc. in theExamples and the rest of the specification are by weight. Table 1provides a role and a source for materials used in the Examples below:

TABLE 1 Materials Function Abbreviation Description Source Monomer 1 iOAIsoOctyl Acrylate 3M, St Paul, MN Monomer 2 AA Acrylic AcidSigma-Aldrich, St Louis, MO Monomer 3 iBOA IsoBornyl Acrylate OSAKAOrganic Chemical Industry LTD, Osaka, Japan Crosslinker1 HDDA1,6-Hexanediol- Sartomer Americas, diacrylate Exton, PA Initiator 1IRGACURE 2,4,6- BASF Corporation, TPO trimethylbenzoyl- Florham Park, NJdiphenylphos- phine oxide Inhibitor BHT 2,6 Di-tert-butyl-Sigma-Aldrich, 4-methyl-phenol St Louis, MO Absorption TINOPAL OBBenzoxazole, BASF Corporation, Modifier CO 2,2′-(2,5- Florham Park, NJthiophenediyl)bis[5- (1,1-dimethylethyl)]

Experimental Apparatus

An apparatus for the continuous additive manufacturing of adhesives wasconstructed as generally depicted in FIG. 1. The actinic radiationtransparent substrate 10 was constructed from an Optically Clear CastAcrylic Tube, 8 inches (20.32 centimeters (cm)) outer diameter×7-¾inches (19.7 cm) inner diameter, cut to a length of 6 inches (15.24 cm),obtained as item 8486K735 from McMaster-Carr, Chicago, Ill., which waswrapped with a clear PET silicone release liner, type RF12N in 5 mil(127 micrometer) thickness, available from SKC Haas, Seoul, Korea. Thusthe siliconized side of the release liner formed the major surface 11 ofthe actinic radiation transparent substrate 10.

Side walls made from flat cast acrylic sheet with a 2 inch (5.08 cm)center hole and smaller access holes were inserted into the Clear CastAcrylic Tube. Bearings with an outer diameter of 2 inches and an innerdiameter of 1 inch were inserted into the 2 inch (5.08 cm) holes,allowing The Clear Cast Acrylic Tube to rotate around a 1 inch (2.54 cm)diameter, stationary, hollow steel tube. The steel tube was attached toa frame constructed from extruded aluminum. A drive system wasconstructed from a 3D printed cogwheel that was attached to the acrylicside wall, and a matching cogwheel on a 12V DC gear motor, modelZGA25RP83i manufactured by Wenzhou Zhengke Electromotor Co., Ltd,Yueqing, China, which was mounted to the extruded aluminum frame.

A 10 mm hole was drilled at the center of the steel tube, and 2 LEDs(One LED emitting 390 nm UV light, model UV3TZ-390-15, and one LEDemitting 405 nm UV light, model UV3TZ-405-15, both available from BivarInc, Irvine, Calif.) with 40 cm cable leads and a 82 ohm resistor wereinserted through the hole and mounted to the stationary hollow steeltube with help of small acrylic bars. The LEDs were facing downwardsinside of the Clear Cast Acrylic Tube, with about 5 mm distance from theinner surface of the tube.

The DC Motor and the 2 LEDs were connected to an Arduino R3microcontroller with Arduino Motor Shield, available from SparkFunElectronics, Niwot, Colo. The microcontroller was programmed to rotatethe Clear Cast Acrylic Tube approximately 30 degrees, then to stop andlight up the LEDs for 2 seconds, the program was set to repeat thissequence for a total of 10 times.

A container 16 with the base plate dimension of 6.5 inches (16.51 cm) by4.5 inches (11.43 cm) and 0.5 inch (1.27 cm) tall side walls wasconstructed from Optically Fluorescent Cast Acrylic, 3/32″ Thick, Amber,available as 85635K471 from McMaster-Carr, Chicago, Ill., and placed ona lab jack under the Clear Cast Acrylic Tube.

A “Super Efficient Compressed-Air Air Knife, Aluminum, 6” Air SlotWidth”, available as item 6069K12 from McMaster-Carr, Chicago, Ill., wasfitted to the frame, so that during the rotation of the drum it blowsexcess composition material from the major surface 11 back into thecontainer 16.

A UV Intensity Analyzer, Model 356, from OAI Instruments, San Jose,Calif., was used to measure the intensity and energy of the LEDs at themajor surface 11. The 400 nm broad band sensor was attached to theAnalyzer, and the sensor surface was centered under the LED, with thesensor housing touching the major surface 11. For the 390 nm LED anintensity of 39.3 mW/cm² and an energy dosage of 79.1 mJ/cm² wasmeasured for the 2 second illumination. For the 405 nm LED an intensityof 31.3 mW/cm² and an energy dosage of 63.7 mJ/cm² was measured for the2 second illumination.

Example 1

An actinic radiation polymerizable composition was prepared by charginga 100 ml amber glass jar with 6.25 g AA, 21.9 g iOA and 21.9 g iBOA,0.156 g HDDA, 0.05 g TINOPAL OB CO, 0.05 g BHT and 0.75 g IRGACURE TPO.The jar was sealed and rotated on a laboratory bench top roller MX-T6-Sat approximately 10 RPM for 2 hours.

The composition was poured into the container 16 of the experimentalapparatus and the container was lifted with help of the lab jack, sothat the composition contacted the major surface 11 right underneath theLEDs.

The experimental apparatus was switched on and went through the sequenceof rotating the drum and switching on the LEDs.

It was observed that at the spots that were illuminated by the LEDs dotsof cured adhesive composition were formed. As the drum rotated, thesedots emerged from the liquid composition and the excess liquidcomposition ran off the major surface 11, back into the container 16.The dots were approximately 3 mm in diameter and 0.5 mm in thickness.

A microscopy glass slide was pressed onto the dots, and it was observedthat they adhered to the glass slide. The dots then were post cured for10 minutes in an Asiga Flash UV post cure chamber, available from Asiga,Anaheim Hills, Calif., USA. This post cure chamber contains four 9Wfluorescent bulbs with a peak wavelength of 365 nm, arrangedapproximately 2 inches (5.08 cm) from a 5.5 inch (13.97 cm) by 5.75 inch(14.61 cm) base plate. The UV intensity was measured using the UVIntensity Analyzer, Model 356, from OAI Instruments, San Jose, Calif.,with the 400 nm broad band sensor. A UV intensity of approximately 5.3mW/cm² was found throughout the base plate.

After the post cure the dots were touched, and they felt sticky andadhered to the finger like a pressure sensitive adhesive. A piece ofpaper was pressed on the dots and it was observed that the paper and theglass slide were adhered together.

While the specification has described in detail certain exemplaryembodiments, it will be appreciated that those skilled in the art, uponattaining an understanding of the foregoing, may readily conceive ofalterations to, variations of, and equivalents to these embodiments.Furthermore, all publications and patents referenced herein areincorporated by reference in their entirety to the same extent as ifeach individual publication or patent was specifically and individuallyindicated to be incorporated by reference. Various exemplary embodimentshave been described. These and other embodiments are within the scope ofthe following claims.

1. A method of manufacturing adhesives comprising: obtaining an actinicradiation-polymerizable adhesive precursor composition disposed on amajor surface of an actinic radiation-transparent substrate; irradiatinga first portion of the actinic radiation-polymerizable adhesiveprecursor composition through the actinic radiation-transparentsubstrate for a first irradiation dosage to form a first adhesive;moving the actinic radiation-transparent substrate; and irradiating asecond portion of the actinic radiation-polymerizable adhesive precursorcomposition through the actinic radiation-transparent substrate for asecond irradiation dosage to form a second adhesive.
 2. The method ofclaim 1, further comprising irradiating a third portion of the actinicradiation-polymerizable adhesive precursor composition through theactinic radiation-transparent substrate to form a third adhesive priorto moving the substrate.
 3. The method of claim 2, wherein the firstportion and the third portion are adjacent to or overlapping with eachother and the first irradiation dosage and the third irradiation dosageare not the same, thereby forming an integral adhesive comprising thefirst adhesive and the third adhesive, the integral adhesive comprisinga variable thickness in an axis normal to the actinicradiation-transparent substrate.
 4. The method of claim 3, wherein theintegral adhesive comprises variations in index of refraction.
 5. Themethod of claim 1, further comprising post-curing the first adhesive. 6.The method of claim 1, further comprising removing actinicradiation-polymerizable adhesive precursor composition remaining incontact with the first adhesive after the irradiating using a gas, avacuum, a fluid, or a combination thereof.
 7. The method of claim 1,further comprising removing the first adhesive from the substrate. 8.The method of claim 1, wherein the substrate is in the form of acylinder, and the method further comprises rotating the cylinder througha container holding the actinic radiation-polymerizable adhesiveprecursor composition to dispose the actinic radiation-polymerizableadhesive precursor composition on the substrate.
 9. The method of claim1, wherein the precursor composition is disposed as a pool on the majorsurface of the substrate.
 10. The method of claim 1, wherein the time ofirradiation of the first dosage is shorter than the time of irradiationof the second dosage.
 11. The method of claim 1, wherein the actinicradiation intensity of the first dosage is lower than the actinicradiation intensity of the second dosage.
 12. The method of claim 1,wherein irradiating the first portion occurs before irradiating thesecond portion.
 13. The method of claim 1, wherein the first adhesive isa pressure sensitive adhesive (PSA), a structural adhesive, a structuralhybrid adhesive, a hot melt adhesive, or a combination thereof.
 14. Themethod of claim 1, wherein the actinic radiation-polymerizable adhesiveprecursor composition comprises an acrylate, a two-part acrylate andepoxy system, a two-part acrylate and urethane system, or a combinationthereof.
 15. The method of claim 1, wherein the actinic radiation isprovided by a digital light projector (DLP) with a light emitting diode(LED), a DLP with a lamp, a laser scanning device with a laser, a liquidcrystal display (LCD) panel with a backlight, a photomask with a lamp,or a photomask with an LED.
 16. The method of claim 1, wherein thesubstrate comprises a multilayer construction.
 17. The method of claim1, wherein the actinic radiation-polymerizable adhesive precursorcomposition includes at least one solvent.
 18. The method of claim 1,wherein the method is performed at a temperature between 20 degreesCelsius and 150 degrees Celsius, inclusive.
 19. A method ofmanufacturing adhesives comprising: obtaining an actinicradiation-polymerizable adhesive precursor composition disposed on amajor surface of an actinic radiation-transparent substrate; irradiatinga first portion of the actinic radiation-polymerizable adhesiveprecursor composition through the actinic radiation-transparentsubstrate for a first irradiation dosage; irradiating a second portionof the actinic radiation-polymerizable adhesive precursor compositionthrough the actinic radiation-transparent substrate for a secondirradiation dosage, wherein the first portion and the second portion areadjacent to or overlapping with each other and the first irradiationdosage and the second irradiation dosage are not the same, therebyforming an integral adhesive comprising a variable thickness in an axisnormal to the actinic radiation-transparent substrate; and moving theactinic radiation-transparent substrate.